#include<stdio.h>
#include<math.h>
int check_if_is_prime(int n);
int check_if_is_palindromes(int n);
int main(void)
{
	int min,max,i;
	scanf("%d %d",&min,&max);
	for(i=min;i<=max;i++)
		if(check_if_is_prime(i)&&check_if_is_palindromes(i))
		 printf("%d\n",i);
	return 0;
}
int check_if_is_prime(int n){
	int i;
	for(i=2;i<=sqrt(n);i++)
		if(n%i==0&&i!=n)
			return 0;
	return 1;
}
int check_if_is_palindromes(int n){
	int each_turn[9];
	int sub_each_turn[9];
	int i,k,counter;
	for(i=0;n>0;i++){
		if(n<10){
			each_turn[i]=n;
			n/=10;
		}
		else{
			each_turn[i]=n%10;
			n/=10;
		}
	}
	i-=1;
	counter=i;
	for(k=0;i>=0;i--,k++)
		sub_each_turn[k]=each_turn[i];
	for(i=0,k=0;i<=counter;i++,k++)
		if(sub_each_turn[k]!=each_turn[i])
			return 0;
			
	return 1;	
}